Pressure control for muller rollers



July 25, 1933. H. K. KING PRESSURE CONTROL FOR MULLER ROLLERS Filed Nov. 14, 1950 2 Sheets-Sheet l -[wen tor flZzUamZJK K5150,

July 25, 1933. H. K. KING PRESSURE CONTROL FOR MULLER ROLLERS Filed Nov. 14, 1930 2 Sheets-Sheet 2 l IE Indenior: ,ZTOwarrdKYKb Patented July 25, 1933 UNITED STATES.

PATENT OFFICE HOWARD K. 'KYING, or PHILADELPHIA, ,PENNSYL'VAN A, AssIcnoR TO "CHAMBERS BROTHERS COMPANY, A CORPORATION-F PENNSYLVANIA 1 PRESSURE co v'rRoLroR MULLER. nonnnns Application filed November 14,1930. Seri a1 No.495,68 2.

The invention relates to pressure control for muller rollers for dry pans, used for elastic medium for controlling the down-' ward movementof the roller toward the end of said movement.

The invention comprises means including a restricted vent for elastic medium for controlling the speed of said downward movement.

The invention comprises meansfor preventing return, flow of compressed elastic medium to its source upon upward movement of the roller, so that said upward movement is accompanied by an increase of said augmented pressure.

The invention comprises means for relieving pressure above a given maximum upon upward movement of the roller.

Referring to the drawings, which illustrate merely by way of example, suitable means for eflecting the invention Fig. 1 is an elevation on a reduced scale as compared with the other figures.

Fig. 2 is a section on line 2, 2 of Fig. 1.

Fig. 3 is a vertical section onan enlarged scale of a cylinder and associated parts.

Fig. 4 is a fragmentary section, on "the plane of line 4 of Fig. 3.

Fig. 5, is a top or plan view of the cylinder shown on Figs. 3 and 4.

Similar numerals refer to similar parts throughout the several views.

In Fig. 1 is shown a usual form of dry pan grinders having the rotating pan 7, and equipped with mullerrollers 8, but

' provided with the improved pressure con.-

trol in accordance with my invention. The rollers 8 are each mounted on an axle 12 having bearings in a double armed bearing yoke 9, and each yoke in turn is mounted on a horizontal shaft 10, so that each yoke may rock to permit its roller to .rise' and fall as it' travels over the material in the rotating pan.

It has beencommon practice to make these rollers very large and heavyin order to secure, by their sheer weight, the necessary crushing power. Various efforts have been made also to augment the pressure of' the rollers, such as by theuse of springs or pressure cylinders. v

The object of the present invention is to secure the required crushing pressure'of the roller without undue increase in its size, and

at the same time maintain an automatic control of the roller movement and pressure, in order to adaptthe machine to the varying character of the material to be operated upon and to add to the safety, efficiency and uniform operation of the machine. I

In accordance with the present example,

' the outer end 11 of each yoke arm is extended beyond the bearing for the roller axle/12, and is provided with a vertical slot 13, into which is inserted and pivotally connected,

as at 14, the turnbuckle or link 15. To this link or turnbuckle 15 is adjustably secured the piston rod 16, and locked therewith in required position of adjustment, by lock nut 17. The rod 16 is connected to the piston 18, operating in cylinder 19. The

cylinder 19 is hung by a pair of" ears or lugs 20 upon a supporting pin 21 so as to have a' slight rocking movement thereon, to accommodate the slight arcuate movement of the lower end of the piston rod which is attached to the rock yoke. The

pin 21 is secured to a substantial supporting frame 27; 1

As each arm of each. yoke, in the present exampleyis connected to a piston rod, it

will be understood that the crushing pressure of each roller is supported controlled by two cylinders.

It will however be obvious that, in some cases, a single arm of each yoke may be connected to a piston rod, in which case a roller may be controlled by asingle cylinder.

Compressed air, at required pressure from a suitable source, not shown, is introduced into the top of cylinder 19 through piping 22 and check valve 23. A safety valve 24: is also connected with the cylinder 19 to prevent excessive pressures; A check valve 25 is connected to the cylinder 19, at a point slightly above the bottom thereof, for permitting the inlet of air to the cylinder but preventing discharge from the cylinder of air therethrough.

A restricted air discharge vent 26 is provided near the lower end of the cylinder,"

but suiiiciently above the bottom thereof to provide an air cushion beneath the piston 18, see Fig.

In operation Air pressure is supplied to the cylinder from a source of air pressure supply; not shown. This pressure may be maintained at any value required to secureeiiicient operation with respect to the material under treatment. For example, this pressure may range from. sixty pounds per squareinch to two hundred and fifty pounds per square inch, and this pressure, as developed upon the piston within the cylinder, is added to the normal gravity crushing pressure exerted by the roller.

When a roller encounters a hard lump or body of material that it cannot immediateply crush, it is lifted by the material, with the piston 18 connected thereto, against the pressure of compressed air in the cylinder 19 above the piston 18, and, due to the action of the check valve 23 in the air pres- .sure line, the volume of compressed air within the cylinder above the piston is trapped or restrained and further compressed. In this way the crushing pressure of the roller increases with its upward movement. This tends instantly to crushlarge or stubborn pieces. v

The purpose of the check valve 25 is. to permit the inflow of air behind the piston in its upward movement and thus maintain the air beneath the piston during its. upward movement at atmospheric pressure This air is utilized to prevent the roller dropping suddenly in the pan bottom. The

purpose of the restricted discharge vent 26, is gradually to relieve the pressure beneath the piston upon 1ts downward movement so as to prevent sudden engagement between the roller andpan. The speed of downward movement of the roller may be regulated by controllingthe size of the vent.

opening. i r

' respect tothe pan.

What I claim is 1. In a 'muller roller control, means for normally utilizing the force of a bodytof compressed elasticfluid medium for augmenting the crushing. pressure of the roller, and means effective upon the upward move I ment'of the roller-for trapping and further compressing a relatively small portion of i said body of compressed elastic fluid, thereby automatically increasing said augmented pressure. V

2. In a muller roller control, means comprising a cylinder and a piston operating therein, for utilizing the force of a compressed elastic fluid medium for augmenting the crushing pressure of the roller, andmeans, comprising a vent in the cylinder adapted to be closed by the piston prior to the end of its downstroke for automatically arresting the downward movement of the roller.-

3. Ina muller roller control, means, in-

eluding a cylinder and a piston operating thereln, for utilizlng the force of a compressed elastic fluid mediumto augment the crushing pressure of the roller, and means, comprising a, restricted vent near the lower end of the cylinder adapted to be overrun by the piston for first retarding and then arresting its downward movement.

4. In a pressure con rol for 'a muller roller, the combination with said muller roller of a movable bearing Qtherefor, a vcylinder,

necting the piston directly to the movable bearing, means for normally establishing communication between the cylinder and a source of elasticmedium under pressure, and means for automatically trapping in the cylinder above the piston a portion of the coma pistonoperating therein, a piston rod coni pressed elastic medium upon the upward movement of the piston; whereby the trapped medium is additionally compressed in direct proportion to the reduced space 111 the cylinder above the piston due ward piston movement.

HOWARD K. KING.

to said up- 

